(1) Field of the Invention
This invention relates to novel 3(2H)-pyridazinone derivatives; preparation thereof; insecticidal, acaricidal, nematicidal, fungicidal compositions for agricultural and horticultural uses; and expellent compositions for ticks parasitic on animals; said compositions containing said derivatives as an active ingredient.
(2) Description of the Prior Art:
The present inventors have previously found a part of the 3(2H)-pyridazinone derivatives represented by the following formula (IV) exhibits agricultural and horticultural insecticidal, acaricidal, nematicidal, fungicidal action (refer to European Laid-Open Patent Application Nos. 0088384 and 0134439): ##STR3## (wherein, for example, R' denotes an alkyl; A' denotes a halogen; R.sup.10 and R.sup.11 denote hydrogen atom or a lower alkyl; X' denotes oxygen or sulfur atom; and Y" denotes a lower alkyl, a cycloalkyl, a lower alkoxy, a lower haloalkyl, a lower haloalkoxy or a substituted phenyl).
The present inventors have further conducted researches on pyridazinone derivatives and have found that the compounds of the present invention represented by the general formula (I) given below have an excellent insecticidal, acaricidal, nematicidal and/or fungicidal action. For example, with respect to fungicidal action, the compounds represented by the general formula (IV) are effective against powdery mildew and downy mildew whereas the compounds of the present invention exhibit a strong action against red rust, rice blight and the like in addition to the above mentioned diseases, which clearly shows a wider fungicidal spectrum of the present compounds. Moreover, it was found that the compounds of the present invention have a higher activity than the known compounds represented by the formula (IV) and can effectively contol organisms which are agriculturally and horticulturally harmful even with an extremely low drug concentration. Thus, the present inventors have completed the present invention. These effects are clearly shown by the test examples given below.